1. Field of the Invention
This invention relates to product dispensing containers wherein the container contents are forced out by internal pressure, usually under control of a valve at the top of the container. More particularly, this invention relates to a sealed package to be inserted in such a container to develop the dispensing pressure.
2. Description of the Prior Art
U.S. Pat. No. 3,718,236 discloses a system for generating pressure within a dispensing container by mechanically combining two or more reactive chemicals in a sealed bag-like structure free-floating within the container. In one disclosed arrangement, the bag includes a number of sealed compartments containing sodium bicarbonate which are ruptured to combine that chemical with a mixture of citric acid and water so as to develop gas pressure within the bag. The rupturing of these compartments is carried out sequentially as the dispensing operation proceeds, in order to develop successive increments of additional pressurized gas as required to maintain an approximately constant pressure within the container as the contents are dispensed.
The bag-like structures shown in U.S. Pat. No. 3,718,236 are relatively complex and difficult to manufacture by conventional processes. Although the basic structure can be sub-divided into simpler components for separate manufacture, that approach requires processing by at least two different types of machines to make the complete assembly, thus resulting in undesirably high cost.